1. Technical Field
The present invention is directed to isolation, purification and characterization of a specific serologic marker for non-A, non-B hepatitis (NANBH). More particularly, the present invention is related to obtaining an isolated, purified antigen associated with non-A, non-B hepatitis causing factor for use in in vitro detection kits and for use as a vaccine against NANBH.
2. Prior Art
Hepatitis non-A, non-B accounts for 20%-40% of sporadic cases of hepatitis among adults in the United States. This type of hepatitis accounts for 90% of post-transfusion hepatitis. An alarming 50% of these cases develop chronic NANBH, and such individuals remain as potential sources of infection. Evidence for the existence of a transmissible agent in this disease has been demonstrated by the infection of chimpanzees by inoculation with serum from a chronic non-A, non-B hepatitis patient, and by serial passage to additional chimpanzees. It may be further noted that chimpanzees have been accepted as surrogate human models for testing purposes and that the diagnosis of NANBH is based upon the exclusion of other human hepatotropic viruses usually by avaialble serologic tests specific for these other agents.
Shirachi et al, Lancet, 853-856 (1978); and Tabor et al, J. Med. Virol. 4, 161-169 (1979) amongst others reported the presence of antigen-antibody tests, all of which suffer the disadvantages of non-specificity, insensitivity, and most importantly, the uncertainty of viral or host origin of the antigens and antibodies. The present invention discloses purified antigen which for the first time provides direct means for detecting Non-A, Non-B hepatitis without cross-reacting with other viral or host antigens.
It may be noted that heretofore the diagnosis of this disease relied on the serologic exclusion of other hepatotropic human viruses such as hepatitis A, hepatitis B, cytomegalovirus and Epstein-Barr virus.